This invention relates to a workpiece changer for automatically placing a workpiece on the worktable of a machine tool and for replacing the workpiece with another workpiece when machining operations on the first workpiece are completed.
An example of a prior art workpiece changer is disclosed in U.S. Pat. No. 3,825,245 which was issued on July 23, 1974, for a "Workpiece Changer Mechanism for a Machine Tool." This workpiece changer includes a workpiece storage support which is rotatably mounted on a frame at one end of the worktable X axis ways and has guideways for slideably receiving a pallet carrying a workpiece, the guideways being alignable with similar guideways on the worktable so that a pallet can be slid along the X axis from the workpiece storage support to the worktable and vice versa. The workpiece storage support is long enough to hold two pallets at the same time and can be rotated by 180.degree. to interchage the position of the two pallets with respect to the worktable. The rotatable portion of the workpiece storage support includes a pair of hydraulic rams with separate hydraulic control systems which are each engageable with a corresponding pallet at opposite ends of the workpiece storage support to slide the pallet along the X axis from the workpiece storage support to the worktable or vice versa. The hydraulic rams and their hydraulic control systems are shown in FIGS. 9-12 of the above-noted patent.